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Homework Problems

 

HW#12   Ch 4: Motion in Two and Three Dimensions

Instructions: Write the general equation before showing your work to earn full credit. Ignore air resistance in the following problems.

1.    Johan Remen Evensen holds the record for the longest ski jump of 246.5 m at Vikersundbakken in Norway. If his initial velocity at the end of the ramp were 29.2 m/s at a downward angle of 5°, how far would he travel downhill without the benefit of the lift force provided by the air pushing against his body? Assume that he lands on a hill with a straight downward slope of 32.7° relative to the horizon.

2.    In 2008, Ryan Capes set a world record by jumping a horizontal distance of nearly 400 feet on a motocross bike. What minimum speed in mph would he require at the end of the ramp to jump this distance, if the ramp angle was 40°? (If one factors in air resistance, his speed would need to be 20 mph greater).

3.    A kicker attempts to kick a field goal with an initial velocity of 25.0 m/s at an angle of 46.5° with respect to the horizon. If the crossbar is 3.046 m off the ground, will the kicker have enough distance to kick a 60-yard field goal?

4.    A spring gun, oriented at 60° with respect to the horizon, fires a 240-gram projectile into the air. While in the barrel of the gun, the projectile accelerates at 550 m/s2 for 40 milliseconds. What is the velocity of the projectile at its highest point while it is in freefall?